How to delete songs from iphone 4?

You cant delete from your phone directly. You must go into Itunes, click on your Iphone on the left. Go into MUSIC and deselect the files from the playlists that you synch. By defualt it does all the artists and songs, but you can deselect them from there.

Does the song you try to remove from your iPhone belongs also in a playlist ?

It can be that since it already belongs to a playlist you need maybe to modify the playlist.

I had this same problem. Here's what I did to fix it.

1. Connect Iphone to Mac

2. Open Itunes

3. Select Iphone in Left

4. Select Manually Manage Music Under Options

5. Sync Iphone

6. Select Iphone/Music

7. Select all Tracks

8. Uncheck all Tracks

9. Sync Iphone

10. Select Iphone/Music

11. Select all tracks

12. Right click, Delete

13. Confirm deletion dialogue

14. Sync Iphone

Then I unselected the manage music maunually option and synced from my library as I wanted.

D DeVille,

When I get to #4, I can't find the Options setting so I can click Manually Manage Music. Can you help me?

Sure, it's on the Summary Page when you select the Iphone. It's at the bottom of the page under the heading Options:

I've also subsequently found that in iOS 5.01, you can delete a song from the iPhone by swiping left to right on it's title in a playlist.

I don't have that option! It only says to manage videos.

That's strange. It could be a version difference. I'm running Mac OSX Lion 64 bit and running 10.5.1(46) 64 bit Itunes.